As water changes from a liquid to a frozen solid, it expands – and when this happens inside your irrigation systems, it can cause expensive and inconvenient damages when the temperature rises and your lawn awakens after a dormant winter. It’s not just the danger of pipes bursting; freezing can damage valves, fittings, nozzles, and essentially any other sprinkler system component that water enters.

So how can you prevent damage? By preparing your irrigation systems properly through a process called winterization, which is basically just landscape-speak for “preparing irrigation for winter months.”

The general procedure of winterization is the same, but the processes are sometimes different, depending on your specific system:

Step 1: Run the water to check for leaks.

Run the water and survey each line and nozzle for leaking or broken heads, and make the necessary repairs prior to shutting the water off.

Step 2: Shut the main valve off.

To locate the main valve, look between the main water supply to your home and the sprinkler controller. It is sometimes in a basement, and other times outdoors. Don’t be afraid if it’s hard to turn – if it hasn’t been turned on or off in a long time, you may need pliers to open it – BUT do not force it if pliers aren’t working. This can break the valve and cause water loss!

Step 3: Drain all water.

Depending on your system, you may be able to do this manually through the drain valves (located near the main shut off valve) or automatically:

  • To drain manual irrigation systems: open all main drain valves and allow all water to drain, making sure all water also drains from the backflow device, piping, and sprinkler heads. Then, close the drain valves.
  • To drain automatic irrigation systems: relieve the system’s pressure to below 10 PSI to activate the auto-drain. Also make sure that all water is drained from the backflow device, piping, and sprinkler heads. Then, close the drain valves.

Note: sometimes locating these valves can be difficult, especially if over time their valve boxes have been covered with overgrowth. One way to identify them is to work with a partner and turn the water on, and notice where the pressure comes out first, the most. That’s likely the nozzle located directly next to a main valve. If that doesn’t work, just give us a call – we’re happy to help!

Step 4: Blow out any remaining water.

To drain an irrigation system with the blow-out (air compressor) method, we recommend hiring a professional, as it can be pretty dangerous and costly if done incorrectly; there are debris that can get in your eyes and potential for causing damage to your irrigation system – including melting the pipes! There are also little details that are easy to forget: isolation ball valves must be closed, flow sensors must be removed, and only certain PSIs can be used.

Step 5: Empty and open the drain valve.

After blowing the remaining liquid, open the drain valve to get the very last of the liquid out – and leave it open. The drain valve should remain OPEN during winter.

Step 6: Turn off or adjust controller settings.

If you are running an automatic irrigation system, you likely want to turn it OFF, unless you have (and trust) a rain-mode setting. If rain-mode setting is available, we suggest choosing it, since it will keep programmed times, but simply will not send the signal to the valves to activate.

If you feel more comfortable turning it OFF, it’s totally no big deal – you’ll just have to reprogram the times and settings when you power it back on. For extra caution, you can shut off the power to the controller and remove the wires that connected “MV” to “common.”

Step 7: Insulate anything exposed.

Whenever possible, it’s best to bury your irrigation lines, but if not, purchase self-sticking foam-insulating tape or foam-insulating tubes for your lines. Additionally, invest in a backflow blanket for insulation on your backflow preventer.

Failing to properly prepare your irrigation systems before the temperatures drop can lead to costly repairs when the weather warms up again, and even if the repairs aren’t imminent, systems that are improperly maintained will weather and wear faster, meaning you’ll have to replace parts and systems sooner than later.

Winterizing your irrigation systems ensures optimal performance come warmer months – but we know it can seem like quite a lot of work! Give us a call today and we’ll be happy to schedule maintenance.